1. Field of the Invention
The present invention relates generally to foam injection molded bicycle helmets, and more specifically to a method for making a bicycle helmet having a novel planar-molded infrastructure about which the helmet is formed.
2. Brief Description of the Prior Art
Foam molded bicycle helmets were first introduced on the market by Applicant in 1985. These helmets were not only light-weight and stylishly designed, but also offered surprisingly effective protection to bicycle riders against head injuries. It was found that by injection molding the shell of the helmet out of foam, injected at a density of about 5 1/2 pounds per cubic foot, a rigid, light-weight helmet could be formed that was capable of meeting and exceeding all applicable safety standards for such helmets. These helmets, weighing approximately 6 ounces, were not only found to protect riders involved in high range collisions (i.e., a 50-60 mile per hour collision with a wall), but also those involved in low range collisions (i.e., falls from 4-5 feet from the ground).
Shortly after these helmets appeared on the market, a number of copies of the helmets began to surface. These helmets, unlike the originally designed helmets, were of lower quality and experienced a difficult time passing safety standards. A number of these helmets were found to fracture upon impact and break into two or more pieces, thereby proving to be completely ineffective or increasing the possibility for further injury in the event the rider's head bounced after initial impact. Even Applicant's helmets were found to experience some problem with breakage when subject to extremely high end collisions or particularly bizarre accidents.
To resolve this problem, different manufacturers have tried a number of different solutions. Some manufacturers, who had previously been using fabric caps stretched over the helmet as a stylish indicator of origin, attempted to use the caps to help keep the helmets together. Fabric caps have proven to be ineffective for this purpose. Other manufacturers have attempted to wrap tape or other reinforcing material around a portion of the lower perimeter of the helmet. This solution has not been generally effective because only a small portion of the overall helmet has been protected. Finally, some manufacturers have even imbedded strips of a fish-net like material into the helmet itself. While the netting protects a larger portion of the overall helmet, it is difficult to imbed the netting within the helmet during the manufacturing process, the netting still does not protect the entire helmet or provide sufficient structural stability, and it can cause unsightly deformations in the surface of the helmet.
Even the smallest decrease in weight of equipment worn by professional bicycle riders can result in a significant change in the amount of time required to race a certain distance. In addition, improved equipment aerodynamics can also have a significant impact on a rider's time. Hence, a number of helmets have been developed which have air passages formed in the surface of the helmet to improve aerodynamics, reduce weight, and provide air conditioning to the rider's head. A non-reinforced helmet can only have a small quantity of the helmet's total area dedicated to air passages for it to be able to maintain integrity upon impact. The netting or other materials used to reinforce some helmets can also restrict the quantity and area of the helmet which can be dedicated to air passages because some materials obstruct the passages and other materials become weakened when cut to produce passages. Thus, another type of reinforcement is needed to solve the problems associated with producing a truly light-weight, aerodynamic bicycle safety helmet.